Implantable electrical signal generators, such as pacemakers, defibrillators, neurostimulators, and the like, have been used to treat a variety of diseases. Such devices generate electrical signals that are transferred to a patient's tissue through electrodes present on a distal end portion of a lead. Many devices include stimulation electronics coupled to an electrical power supply, such as a battery. In many cases, the power supply is electromechanically coupled to the stimulation electronics with a robust connection suitable for providing the power required by the stimulation electronics. In some cases, the connection is formed by welding at a power terminal. However, various power supplies include components that are susceptible to melting at high welding temperatures, such as separators between plate electrodes in a rechargeable battery. Accordingly, forming a robust electromechanical connection at a power terminal presents particular challenges.